Slots Garden Casino Denied Payout and locked me out of my account. Internet Internet

I have been playing on Slots Garden for a while and just using the credit they give you but decided on May 12, 2017 to make a deposit and play real money.  I made a deposit of $60 and played all evening, ended up with several free spins and won $400.  I played a little longer and got up to about $600 and then played it back down to $400.  I then requested a payout of $300 of my winnings.  I had to submit it to finance for approval.  The next day I tried to login and play with the $100 I had left on my account and they had locked me out.  I called customer service and was told that finance had locked me out and did not give me a reason other than I just could not play until further notice.  When I asked to speak to finance I was told they would not be in until Tuesday and it was Friday.  I waited until Tuesday and had not heard anything, tried to log into my account and still locked out immediatly after I tried to login I receive and email and this is what it said "We're sorry, but your CourierChk payout request of $ 300.00 USD for Account ID mommabass has been declined.Payout Comments:We thank you for your continued business and are always available if you should have any questions."  I replied back stating I wanted an explanation and nothing from them in return.  How can you run an online casino where people pay their own money and win then you do not pay them their winnings sounds illegal to me. 

I just want to know what I am supposed to do at this point, am I just out of luck?  I have read comments on their FaceBook page that many people have been done this way, which I wish I would have seen this before I played.